\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{tikzpicture}[>=latex,scale=1.0]
  % \useasboundingbox(-2,-2.2)rectangle(2,1.5);
  \fill[cyan!20!lightgray,opacity=0.4,draw=black](-0.05,-0.6)[rounded corners]--(-0.05,-0.2)[sharp corners]--(-3,-0.2)arc(270:90:0.2)--(3,0.2)arc(90:-90:0.2)[rounded corners]--(0.05,-0.2)--(0.05,-0.6);
  \draw[thick](-3,-0.15)--(-3,0.15)(3,-0.15)--(3,0.15);
  \draw[->,thin](0,-0.4)--++(0,-0.5)node[below]{接抽气机};
  \draw(-3,0)--(-4,0)--(-4,1.0)[-o]--(-1,1.0);
  \draw(3,0)--(4,0)--(4,1.0)[-o]--(1,1.0);
  \node at (0,1.0)[above]{接高压电源};
  \end{tikzpicture}
\end{document}